If you have a local machine shop that does motorcycle cylinder boring/honing.
They might be able to put you in touch with a supplier. When I had my ATC 200 done, my machinist supplied the new piston and rings.

Already tried that, but good idea. My local Honda dealer said they could not get them and my local machine shop that does a lot of bikes said that they could not get the rings either...

There are two TDC points in a four stroke cylinder. TDC on compression , and TDC on overlap .

You need to adjust the valves on the compression stroke which is when there will be clearance at the valve adjusters. If the engine wants to "turn away" from TDC it's probably on the overlap stroke in which both valves are slightly open.

Turn the engine another 360 degrees and see if it is happy to stay at TDC. I suspect that's the problem and you should find that there is clearance at the valve adjusters too.

Another way to ensure you're at the correct TDC is to watch the inlet valve open, then close... you want the next TDC after it closes.

They want to turn away on TDC of the compression stroke as well. I found that using a larger wrench helps. When you get close to the spot where the "T" mark is, make sure the wieght of the wrench/breaker bar is holding the motor from rotating. I always tried to stop just before the "T", because after TDC the motor will turn away worse.

I gave up trying to use feeler gauges to set the gap, because they always rubbed on the tiny valve cover openings. I just wiggled the rocker arms, and set the exhaust a tiny bit looser than the intakes. After just a few tries, I could get it right on the first attempt.

After a week of daily riding to/from work (20 miles per day), my sealed beam headlight blew out. I understand this is fairly common with the old XLs with the headlight circuit coming off the stator. I could pay $40 for a new headlight on eBay, but then it'd probably blow again.

What are my options? Is there another model XL (or a later year) that doesn't use the sealed beam headlight? I'd rather just replace the bulb than the whole unit.

If I can't find a non-sealed unit, I'll probably fab my own 6-volt LED system with volt/amp regulators, which would give me an excuse to use the 3D printer we just got at work. (Has anyone tried that before?)

After a week of daily riding to/from work (20 miles per day), my sealed beam headlight blew out. I understand this is fairly common with the old XLs with the headlight circuit coming off the stator. I could pay $40 for a new headlight on eBay, but then it'd probably blow again.

What are my options? Is there another model XL (or a later year) that doesn't use the sealed beam headlight? I'd rather just replace the bulb than the whole unit.

If I can't find a non-sealed unit, I'll probably fab my own 6-volt LED system with volt/amp regulators, which would give me an excuse to use the 3D printer we just got at work. (Has anyone tried that before?)

I don't know what headlight the 185 uses, but most of the Asian/Euro/Australian market bikes use a reflector with a replaceable lamp you may want to figure out what the cross reference part number is. For 72-75 (and maybe 76-78) XL250s and XL350s it's 33100-439-003, that may work for you as well but I really don't know. The 250s and 350s use an odd 5" diameter reflector. The other alternative is to adapt a 5 3/4 E2 reflector, which is what I did, my bikes have Cibie H4 reflectors now.

After a week of daily riding to/from work (20 miles per day), my sealed beam headlight blew out. I understand this is fairly common with the old XLs with the headlight circuit coming off the stator. I could pay $40 for a new headlight on eBay, but then it'd probably blow again.

What are my options? Is there another model XL (or a later year) that doesn't use the sealed beam headlight? I'd rather just replace the bulb than the whole unit.

If I can't find a non-sealed unit, I'll probably fab my own 6-volt LED system with volt/amp regulators, which would give me an excuse to use the 3D printer we just got at work. (Has anyone tried that before?)

I love the 185. I had an '83 that would start 1st kick every time, with no need to find the compression stroke.

My XL600R had a UFO headight, but I don't know where the previous owner got it. It was nice and bright, and lasted for 10+ years. That bulb was square, though.

Actually, this website seems to have almost every single part for my 1979 Xr500 that I want. I have never dealt with them before, so hopefully the inventory their website shows is accurate...

I would still be interested other palces to buy the vintage Honda XL / XR parts though...

Update: CheapCycleParts canceled my oreder, they can NOT get the OEM honda rings, even though they are listed on the website.

After extensive searching and calling, I have not found anyone who can get me OEM rings.

Amazon.com sells Wiseco piston kits for the XL/XR models dirt cheap. I got a forged 10.5:1 piston with rings, pin, and clips for $150 including two day shipping. You can not beat this price!! I just thought someone else may benefit from this info...

Update: CheapCycleParts canceled my oreder, they can NOT get the OEM honda rings, even though they are listed on the website.

After extensive searching and calling, I have not found anyone who can get me OEM rings.

Amazon.com sells Wiseco piston kits for the XL/XR models dirt cheap. I got a forged 10.5:1 piston with rings, pin, and clips for $150 including two day shipping. You can not beat this price!! I just thought someone else may benefit from this info...

Honda discontinued a lot of those parts, so they may be just gone forever. Here are a few places to call:

Update: CheapCycleParts canceled my oreder, they can NOT get the OEM honda rings, even though they are listed on the website.

After extensive searching and calling, I have not found anyone who can get me OEM rings.

Amazon.com sells Wiseco piston kits for the XL/XR models dirt cheap. I got a forged 10.5:1 piston with rings, pin, and clips for $150 including two day shipping. You can not beat this price!! I just thought someone else may benefit from this info...

the '76 250 is the odd duck of the bunch- only made it that one year in the states... Not sure if the '76-'78 XL 350 heads are the same or not but I'm pretty sure none of the '72-'75 cylinders will fit and I know the heads won't. The bottom end is pretty much identical to the later 350's though as I understand.